Question: Luis has rowed his boat for a total of $20$ kilometers since he started rowing daily. He has been rowing $4$ kilometers each day. For how many days has Luis been rowing?
The number of days that Luis has been rowing is the total number of kilometers rowed divided by the number of kilometers rowed each day. $20\text{ kilometers} \div 4\text{ kilometers per day} = \text{number of days rowing}$ $20\text{ kilometers} \div 4\text{ kilometers per day} = 5\text{ days}$